By reading this, I take it that you have seen / or are familiar with the characters, as background knowledge is needed to understand this review. I have not read the light novels nor read the manga.This is all based on the first season, as well as this OVA.
Ro-Kyu-Bu OVA is a story primarily focused on Tomoka. And how much her friends care for her. By that said, some fanservice is always added to make the story more enjoyable. You will either enjoy this or you will detest how the OVA presents it.
Speaking of characters. There's nothing much to say. We get to know the characters better, the bound is getting stronger. And we are getting excited for season two. However, a new character is introduced. She gets some screen time, but will she get more screen time in season two? This is still a question, and we still don't know if she will have an impact on the story. The sad thing is that not every character from season one got screen time in this OVA. I hope they will make a comeback in season two! (Gogo sidecharacters!!)
Unfortunately, the OP and ED is the same as the first season. But this is to be expected as this OVA is an episode which leads to season two. Luckily the OST is the same old, good soundtracks. (and if you have not heard the characters song, I recommend you to). A thing which really caught my attention is the Party love! song in an instrumental version played by a violin. I cant recall this from season one, however, it made a good impact on me. And I really loved it.
Personally, I am a big fan of this series. And was really glad when it announced an OVA AND a second season. The artwork has a big role here. This type of artwork is really beautiful in my opinion. And I will never get tired of it. The producers have done a great job forming this anime. Regarding the enjoyment, you may call me whatever you want, but personally I find this OVA really enjoyable. I was really smiling while watching. However, if you are a person who dislikes this sort of anime, you might find this OVA with this particularly fanservice rather boring or pointless. However, if you find it ok, or with an 'it's better than nothing thought'. I will really recommend you to watch this simple little OVA. It might possibly lighten up your day!
Like I mentioned before, the entire story shows the bound of friendship between Tomoka and her friends. This main theme is very visible from the beginning. And personally I think showing the theme from the very beginning is not a wrong direction to start with. The story actually starts with a parallel action, one part being Subaru and Tomoka, and the other part being Tomoka's friend. The connection between these two parts are good simulated. And it shows off the bound between ALL the characters. But the method used to bring these two parts together is rather old school, thus making it way to obvious. But in the end, the story reaches its goal and forms a stronger bound between all the characters. To make the story float, every character have its own 'scene' to show off their good old personality from season one. The OVA ends with a good match of Basket. Thus the theme of basket is still kept. Nothing have changed since the first season as well, and every character are happily gathered to show you an episode of Ro-Kyu-Bu!